Abstract Grains constitute the building blocks of polycrystalline materials and their boundaries determine bulk physical properties like electrical conductivity, diffusivity ductility. However, structure evolution grains in nanostructured role grain reaction or phase transformation kinetics are poorly understood, despite likely importance catalysis, batteries hydrogen energy technology applicat...

Hydriding and dehydriding transitions in bulk nanocrystalline binary metal hydrides were studied using the Pd-H model system by measuring pressure-composition isotherms with situ x-ray diffractometry. Nanocrystalline Pd showed a smaller pressure hysteresis, solvus hysteresis lattice parameter, compared to Pd. The time-dependence of equilibration was measured after dosing aliquots hydrogen, givi...

A 90 wt.% MgH2 – 10 wt.% V2O5 composite was obtained by ball milling of a mixture of magnesium hydride and vanadia for 60 min under argon. Hydrogen sorption properties of the composite were determined volumetrically with a Sieverts-type device. Absorption was studied at temperatures of 473 and 573 K and pressure of 1 MPa, while desorption was investigated at T = 573 and 623 K and P = 0.15 MPa. ...

Thermodynamic parameters of the hydriding reaction of a hydride electrode can be obtained by two different methods. The results show that the change of enthalpy AH, change of entropy AS and hydrogen pressure calculated from e-c-T curves of electrochemical reactions have much larger inherent errors compared with those obtained from p-c-T curves of alloys in hydriding reactions with hydrogen gas ...

Hydrogen storage in metal hydrides presents distinct challenges which encourage the study of effective heat management strategies. absorption is an exothermic reaction, consequently generated must be removed effectively to achieve desired performance. This work a mathematical model describing adsorption hydrogen La Ni4.7Co0.3 hydride as material. Heat and mass transfer effects are modeled detai...

Combined thermodynamical and structural studies have confirmed the occurrence of multimode hydriding/dehydriding reactions of CaPd that vary depending on temperature, and that these reactions proceed via hydrogen solution/dissolution in the temperature range 273-523 K and via phase decomposition/recombination in the temperature range 523-773 K.

As a part of the production of nitride nuclear fuel for use in fast nuclear reactors, zirconium is hydrided followed by nitriding and mixing with uranium nitride. This work concludes a study of unwanted metallic particles present in a powder that is supposed to be a zirconium hydride. Sponge zirconium was hydrided at different temperatures and different time intervals, and the resulting hydride...

The hydrogenation characterizations of the hydrogen storage alloy MmNi4.22Co0.48Mn0.15Al0.15 (Mm= mischmetal), and the effect of hydrogenation/dehydrogenation (H/D) cycling on its structural and morphological properties are investigated. The results indicate that after several H/D cycles the alloy was pulverized into fine particles, but it kept its hexagonal CaCu5-type structure. The pressure-c...

The Journal of Physical Chemistry C is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Article Hydrogen Spillover Enhanced Hydriding Kinetics of Palladium-Doped Lithium Nitride to Lithium Imide Chikai Lin, Tao Xu, Jiamei Yu, Qingfeng Ge, and Zhili Xiao J. Phys. Chem. C, 2009, 113 (19), 8513-8517• Publication Date (Web): 21 April 2009 Downloaded from ...